1. Field of the Invention
The present invention relates, in general, to steel cord take-up spools for storing steel cords, typically used as reinforcement cords for a variety of elastic products, such as steel belted tires, conveyor belts, polyurethane or rubber timing belts or tubes, during a transportation or storage of such steel cords and, more particularly, to a steel cord take-up spool provided with a clip, consisting of a cord clamping part, an undesired cord release preventing part, a bent part, and a clip attaching part and being attached to a rib flange of the spool having a hole and a slit, the clip elastically holding the free end of the steel cord at the inside surface of the rib flange after the steel cord is completely wound around the rib of the spool, thus allowing a user to easily and simply hold or release the free end of the steel cord to or from the rib flange.
2. Description of the Prior Art
In order to produce a steel cord used as a reinforcement cord in the prior art, a plurality of filaments, having a diameter of 0.1 mm-0.4 mm and made of carbon steel having a carbon content of 0.6 wt %-0.95 wt %, are primarily plated with brass to have a brass layer having a thickness of 0.1 m-0.4 m. The brass-plated carbon steel filaments are, thereafter, twisted together by a twisting machine to form a resulting steel cord having a desired strand structure, such as 1xc3x973, 1xc3x974, 2+2, 2+7, 3+6, or 3+9+15 strand structure. Such conventional steel cords are superior in strength, modulus, heat resistance, and fatigue resistance in comparison with conventional organic and inorganic fibers, and so the steel cords have been preferably used as reinforcement cords for a variety of elastic products, such as steel belted tires or conveyor belts.
The conventional process of producing such steel cords is finished at a filament twisting process. In such a filament twisting process, two or more metal filaments from a drawing process are twisted together by a twisting machine to form a resulting steel cord having a desired strand structure. The steel cord is continuously discharged from the cord outlet unit of the twisting machine and is wound around a take-up spool. When a desired length of steel cord is completely wound around one take-up spool, it is necessary to clamp the free end of the cord to the spool.
FIG. 1 is a perspective view of a steel cord take-up spool having a conventional cord clamping structure. In order to clamp the free end of a steel cord on the spool having the conventional cord clamping structure after the steel cord is completely wound around the rib of the spool, the free end xe2x80x9cSoxe2x80x9d of the steel cord xe2x80x9cSxe2x80x9d passes through a small-diameter hole 12, formed on the rib flange 11 of the spool, prior to holding the end xe2x80x9cSoxe2x80x9d of the cord by using a clip 13 fixedly mounted to the outside surface of the rib flange 11. However, the conventional cord clamping structure of the steel cord take-up spool is problematic in that the passing of the free end xe2x80x9cSoxe2x80x9d of the steel cord through the hole 12 is difficult and consumes excessive time and labor. Furthermore, when the free end xe2x80x9cSoxe2x80x9d of the steel cord becomes untwisted, it is almost impossible to pass the free end xe2x80x9cSoxe2x80x9d through the hole 12. Therefore, the conventional cord clamping structure forces the free end xe2x80x9cSoxe2x80x9d of the steel cord to be additionally treated through a taping or welding process to prevent the free end xe2x80x9cSoxe2x80x9d from becoming untwisted. The conventional cord clamping structure of the spool thus reduces productivity while clamping the free end of a steel cord to the spool.
In a conventional process of producing steel belted tires using such steel cords, the steel cords have to be coated with rubber through a calendering process. In such a calendering process, it is typical to feed five hundred or more steel cords from the same number of spools to a calender at the same time. It is thus necessary to release the clamped ends xe2x80x9cSoxe2x80x9d of the five hundred or more steel cords xe2x80x9cSxe2x80x9d from the cord clamping structures of the spools one by one. This regrettably consumes excessive time and labor, and so it is necessary to propose a steel cord take-up spool having a structurally improved cord clamping structure capable of reducing the consumption of time and labor while clamping or releasing the end of a steel cord wound around the spool.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a steel cord take-up spool, which is designed to improve work efficiency while clamping the free end of a steel cord and to conserve time and labor while releasing the clamped end of the steel cord during a calendering process.
Another object of the present invention is to provide a steel cord take-up spool, which is designed to prevent the clamped end of a steel cord from being undesirably released during a transportation or storage of the spools having the steel cords.
In order to accomplish the above objects, the present invention provides a steel cord take-up spool comprising a clip, designed to hold the free end of a steel cord, wound around the rib of the spool, at the inside surface of the rib flange, the clip also having a means for preventing the clamped end of the steel cord from being undesirably released from the rib flange due to external impact.
In a preferred embodiment of the present invention, the steel cord take-up spool, comprising a clip consisting of a cord clamping part used for clamping the free end of a steel cord wound around the spool, an undesired cord release preventing part extending from the cord clamping part and used for preventing the end of the steel cord from being undesirably released from the cord clamping part, a bent part extending from the cord release preventing part and having a crank-shaped cross-section suitable for providing elasticity for the cord clamping part, and an attaching part extending from the bent part and used for attaching the clip to a rib flange of the spool; and the rib flange provided with a hole for allowing the cord release preventing part of the clip to pass through, the rib flange also having a slit designed to allow the attaching part of the clip to pass through and to seat the bent part of the clip therein, whereby the attaching part of the clip passes through the slit of the rib flange in a direction from the inside to the outside surface of the flange prior to being mounted to the outside surface of the flange, the cord clamping part of the clip elastically clamps the free end of the steel cord using elasticity provided by the bent part, and the cord release preventing part is inserted into the hole of the flange in a direction from the inside to the outside surface of the flange and prevents the end of the steel cord from being undesirably released from the cord clamping part of the clip.